Step-up or step-down stabilizer?

Question

Electronics

Can't decide which converter to use. In theory, I want to buy three solar panels (5v; 250mA) and connect them in parallel. Then the stabilizer, which will power either the bank or the phone. It is embarrassing that a step-down dc-dc is used everywhere, but we only have 5 volts, it is more logical to assume that, on the contrary, a step-up is needed. Help to understand, please.

Answer 1

Given that the phone and the power bank already have a converter, you can not fence anything. The voltage is 4 ... 7 volts, which the batteries give out, they will survive.

Answer 2

Let's start with the fact that you need to supply a certain voltage to the phone's power connector, usually a stable 5V to the USB input. If the panels are 5V, then this does not mean at all that they will always give 5V. Therefore, it is better to turn on the panels in series, you will get a voltage of 5.5-15V with this voltage, you can infect a lithium battery through a special charge controller and already from the battery through a boost converter, apply 5V to the phone. Those. you will get a Powerbank on solar charging.

Answer 3

lm7805 вам поможет

Answer 4

То есть получаться в суме максимальный ток 0,75 ма, учти напряжение иногда падает, нужно что-бы было всегда стабильно 5 в, смотри такого плана преобразователь robo4ip.com.ua/povyshayuschie/37-preobrazovatel-na... , он как раз максимум и выдаст 0,7 ма для заряда. Но точно не понижающий!